From the UNIVERSITY OF WATERLOO
Water reservoirs created by damming rivers could have significant impacts on the world’s carbon cycle and climate system that aren’t being accounted for, a new study concludes.
The study, conducted by researchers at the University of Waterloo and the Université libre de Bruxelles, appears in Nature Communications. It found that man-made dam reservoirs trap nearly one-fifth of the organic carbon moving from land to ocean via the world’s rivers.
While they can act as a significant source or sink for carbon dioxide, reservoirs are poorly represented in current climate change models.
“Dams don’t just have local environmental impacts. It’s clear they play a key role in the global carbon cycle and therefore the Earth’s climate,” said Philippe Van Cappellen, a Canada Excellence Research Chair in Ecohydrology at Waterloo and the study’s co-author. “For more accurate climate predictions, we need to better understand the impact of reservoirs.”
There are currently in excess of 70,000 large dams worldwide. With the continuing construction of new dams, more than 90 per cent of the world’s rivers will be fragmented by at least one dam within the next 15 years.
The study’s researchers used a novel method to determine what happens to organic carbon traveling down rivers and were able to capture the impact of more than 70 per cent of the world’s man-made reservoirs by volume. Their model links known physical parameters such as water flow and reservoir size with processes that determine the fate of organic carbon in impounded rivers.
“With the model used in this study, we can better quantify and predict how dams affect carbon exchanges on a global scale,” said Van Cappellen, a professor in Waterloo’s Department of Earth and Environmental Sciences.
In similar recent studies, the group of researchers also found that ongoing dam construction impedes the transport of nutrients such as phosphorus, nitrogen and silicon through river networks. The changes in nutrient flow have global impacts on the quality of water delivered to wetlands, lakes, floodplains and coastal marine areas downstream.
“We’re essentially increasing the number of artificial lakes every time we build a dam,” said Taylor Maavara, lead author and a PhD student at Waterloo. “This changes the flow of water and the materials it carries, including nutrients and carbon.”
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To put those 70,000 reservoirs into proportion.
Finland has 190,000 lakes larger than 1 hectare (2.5 acres), Sweden has about 100,000. Canada has 32,000 lakes larger than 3 km2 (about 1.2 square miles) while the number of smaller lakes is about 2,000,000. Russia has 2,750,000 lakes of which about 50,000 are larger than 1 km2. The US has 120,000 lakes larger than 10 acres.
Doesn’t Minnesota have 10,000?
Very likely. Recently glaciated areas always have lots and lots of lakes. Quite likely North Dakota has even more if you count “prairie potholes”.
Minnesota has 10,000 and Manitoba has 100,000, but who’s counting?
Irrigation, especially spray irrigation, puts about 100 times as much water vapor into the air as everything else combined.
Thanks for that Dan
Quite right. Irrigation, often provided by dams, is a major source of the most important GHG.
Doubtless, yet another study undertaken by recently graduated scientist’s, with no life skills whatsoever, at the behest of their all seeing, all knowing green professor, focussing on one single, tiny element of a massive, social, engineering, environmental, beneficial, genuinely clean, energy producing project that will last for hundreds of years (well OK, submerging entire Welsh or Chinese communities isn’t exactly social).
My point being, is that it seems to me that the research into a great many of these studies is done by kids who are wet behind the ears.
There’s a saying I can’t quite remember, but it goes something like – If you’re not a socialist before you’re 30, you have no heart. If you’re a socialist after you’re 30, you have no sense.
With senseless educators, these impressionable kids are led down the path of green socialism, indoctrinated, and blinded by political idealism they don’t understand.
Am I talking out my a*se? Well possibly, other than my wife runs a University department with 50 or 60 lecturers including Phd qualified staff, and her observation is that the most sensible amongst them are the second/third generation immigrants (so not immigrants at all) who actually maintain touch with reality, having relatives overseas.
The real whacko, nut job, green socialist fanatics, are the indigenous white characters who enjoy their holiday to a Spanish multiplex hotel every year, and maintain they are seasoned travellers.
An accomplished Scholarship fiend . . . wow!
https://uwaterloo.ca/ecohydrology/people-profiles/taylor-maavara
Taylor Maavara’s fantasy World ultimately paid for by us.
About that 90% figure…
“Around half of the world’s rivers now have one or more large dams on them and the total amount of water stored in the world’s reservoir is around 7000 km3, which amounts to nearly a sixth of the total annual riverflow in the world. Nearly two-thirds of the world’s 227 largest rivers are dammed.”
J.A.A. Jones, Water Sustainability: A Global Perspective, Routledge, 2014, p. 117.
7,000 km3 is less than a third of the water in The Great Lakes (or Lake Baikal for that matter).
Good thing they didn’t declare that the increased surface area of dammed reservoirs caused more evaporation of water vapor to the atmosphere and therefore more ‘artificial’ H2O in the atmospheric systems. Water bodies globally on average evaporate about one ton per sq m2 per year so this additional water vapor in the atmosphere is a ‘new’ GHG (H2O) had the dam never impounded the water to begin with. Good thing they don’t consider H2O water vapor a GHG, otherwise it would really mess up their accounting of CO2 in the warming budget. Obviously this additional water vapor turns to precipitation at some point, so might also be part of the increased rainfall in flood prone regions.
With tens of thousands of square miles of new reservoirs the last 100 years, I see no accounting for this fact of increased water vapor in the atmosphere directly as a manmade cause, and that the impounded water behind the dams would add an inch of water to the ocean sea level rise. I know, this is probably an inconvenient truth to the skeptics, but I am just being skeptical here. My point being, is that there are many other causes to the so called AGW theory (which hasn’t provided very much warming by the way) so how can CO2 be responsible for all AGW climate change issues?
“the impounded water behind the dams would add an inch of water to the ocean sea level rise.”
7,000 km3 is equal to slightly less than 3/4 of an inch, and it is probably balanced by draining of natural lakes and wetlands in any case.
“Obviously this additional water vapor turns to precipitation at some point, so might also be part of the increased rainfall in flood prone regions.”
Also, since evapotranspiration is more important for transporting heat away from the Earths surface than infrared radiation it will also cool the global climate a bit.
.
I guess it depends where we source the info from. Some of the results I got were as high as 1.25″ for the additional SLR so I averaged it to 1″. Even 3/4″ of water over the entire ocean is a slug of water. If natural SLR has been about 6″ in the last 100 years or so, then the impoundment of 3/4″ to 1″ water is a good thing and represents about 20% of that increased oceanic water, although a lot of the SLR is thermal expansion.
The additional evapotranspiration would be from the increasing plant growth as a result of the additional greening of the planet due to rising CO2. Good point. I think you are meaning that just plain old evaporation would transport latent heat away resulting in local cooling. But more water vapor in the atmosphere will mean more precipitation, somewhere. The point being that increased rain caused flooding is all the fault of CO2 induced warming they say, although we are proving that there are multiple causes to AGW so CO2 can’t be the sole source of all the perceived problems with man made CAGW.
“The additional evapotranspiration would be from the increasing plant growth as a result of the additional greening of the planet due to rising CO2. Good point. I think you are meaning that just plain old evaporation would transport latent heat away resulting in local cooling.”
No. Any water evaporated, whether from plants, lakes, dams or oceans is relatively quickly transported to high altitude by convection. There it condenses and the freed latent heat is radiated away into space. This is a considerably more important heat transport mechanism than IR radiation, though you have to dig into the physics to find out, because it is never ever mentioned explicitly by “climate scientists”. And, yes, any water evaporaten anywhere always comes back down as rain/snow somewhere.
*more important* than IR?? HA!
…except for all that cooling that happens at night due to infrared radiation
tyy:
The absolute term of “any water evaporated” (implying all water evaporated) is a poor choice of words because if you look at global IR satellite imagery, deep convection I relatively rare so that statement is false
1) that ‘freed latent heat’ is internal to the cloud and only abt 3F warmer than surrounding atmosphere with the equivalent dry parcel being lifted so…no, that is not correct either.
2) tops of the clouds are cold not hot (this is obvious from Skew-T charts & satellite imagery) and if you see hot bare ground next to a cold cloud top in that imagery, it is obvious clear sky is a better radiator of heat than any cold cloud top…especially tall cumulonimbus clouds which can be as cold a -80C.
Obviously it’s not.
“*more important* than IR?? HA!”
It is. IR transports away 66 W/m2, Evapotranspiration 78 W/m2, Thermals (=warm air) 24 W/m2
Those are IPCC figures, though their image is carefully contrived so as to hide this embarrasing fact:
http://wg1.ipcc.ch/publications/wg1-ar4/faq/fig/FAQ-1.1_Fig-1.png
JKrob
I’m sorry to have to say this, but you are ignorant of basic atmosphere physics.
“The absolute term of “any water evaporated” (implying all water evaporated) is a poor choice of words because if you look at global IR satellite imagery, deep convection I relatively rare so that statement is false”
If the statement was false water vapour would be continuosly accumulating in the atmosphere. It isn’t. All evaporated water comes back down, and fairly quickly too. Ten days is the figure usually given.
“tops of the clouds are cold not hot (this is obvious from Skew-T charts & satellite imagery) and if you see hot bare ground next to a cold cloud top in that imagery, it is obvious clear sky is a better radiator of heat than any cold cloud top”
Nope. Ever heard of greenhouse gases? They largely prevent LWIR from the ground reaching space. And the reason those cloud-tops are cold are because they are at an altitude where most LWIR is free to radiate away into space (which is at 3 K). At about 5-6 km altitude they are at Earth’s equilibrum temperature, i e 255 K. Of course this is an average figure, it varies with season and geographically.
The temperature of lake water does not exceed 31C. This does not depend upon if the sky is clear or cloudy. All temperature scales for lakes end at 31C. Why, have you ever noticed when walk on a lake bottom where the water is not flowing, you kick up a grey cloud. That cloud is calcium carbonate. When water gets near 28C, it starts releasing carbon dioxide and that carbon dioxide combines with calcium to from calcium carbonate. In the processes, energy is taken from the water to complete the chemical bonds. This removal of heat is sufficient to limit water temperature to less than 31C.
Ron Williams: Sources for the 1″ lower sea level or whatever? Curious. A dam attenuates the peak flow. There is additional evaporation and probably infiltration but overall close to the same amount of water gets to the ocean, it just gets there with a bit of lag – at least in temperate zones. I keep seeing people inferring that reservoirs cause less water to get to the ocean (which might be ever so slightly true in desert regions) but generally they just reduce the peak flow. Of course I studied hydrology 50+ years ago so maybe there is something new I don’t know about. Even much of the infiltrated or evaporated water finds its way back to another water basin and eventually to the ocean.
Here is a sample of flood routing (which includes through the Oroville Dam):
http://www.damsafety.org/media/Documents/FEMA/TS22_DambreachModeling/20_PRESENTATION.pdf
Others, just references to routing.
http://ce531.groups.et.byu.net/syllabus/homework/hw27/index.htm
http://www.ce.utexas.edu/prof/mckinney/ce374k/Overheads/16-ReservoirandRiverRouting.pdf
“I’m sorry to have to say this, but you are ignorant of basic atmosphere physics.”
and I’m sorry to say you are ignorant of basic meteorology…and you trust IPCC images which, with your example, is what is referred to as a gross oversimplified model (with some errors, I might add).
“All evaporated water comes back down, and fairly quickly too”
but not solely through deep convection as you claim. There are a variety of other precipitation processes (as well as the formation of dew, which *also* removes water vapor from the air without convection). If you knew anything about meteorology, you’d know that.
“Ever heard of greenhouse gases? They largely prevent LWIR from the ground reaching space.”
now that is just ignorant. I never said or implied water vapor does not impact IR radiation to space but it is not as much as you claim because nights still cool down under a clear sky even with water vapor present. Also, if water vapor was as big effect as you claim, not heat would be reaching the satellites to detect which it obviously does. Water vapor only occupies a portion of the total IR spectrum. It’s not all or nothing.
“And the reason those cloud-tops are cold are because they are at an altitude where most LWIR is free to radiate away into space…”
Now that is just laughable. Cloud tops reflect the temperature of the level of the atmosphere they are at (Equilibrium Level – look it up) and it is colder than the surface solely due to the atmospheric laps rate present at that location (look that up too). You obviously have no clue about meteorology.
You obviously have no references to back up your claims & I have around 100 years operational meteorology references to draw from so…I guess they are all wrong & your right.
“ There are a variety of other precipitation processes (as well as the formation of dew, which *also* removes water vapor from the air without convection). If you knew anything about meteorology, you’d know that.”
Yes, and they all liberate the same amount of latent heat, but convective precipitation is a very large part of all precipitation, particularly in the tropics around the ITCZ (where most rain falls):
Here you can watch the convection cells swell and collapse every day
https://www.smhi.se/vadret/nederbord-molnighet/satellit-jorden
“Now that is just laughable. Cloud tops reflect the temperature of the level of the atmosphere they are at (Equilibrium Level – look it up) and it is colder than the surface solely due to the atmospheric laps rate present at that location (look that up too). You obviously have no clue about meteorology.”
Actually I have a degree in meteorology, but that is neither here nor there. However, have you never wondered why there is a lapse rate, and why it happens to be almost exactly equal to the amount of energy needed to lift air of the local relative humidity against the local gravitational field? Yes, I know it varies a bit around that figure, and that this variation is a large part of what meteorologists do for a living.
d know that.”
“I never said or implied water vapor does not impact IR radiation to space but it is not as much as you claim because nights still cool down under a clear sky even with water vapor present. ”
They do indeed, and they would no matter how much GHG are around, because that big yellow thing in the sky isn’t there. If the night was long enough (and heat didn’t transfer from the day side) temperature would ultimately sink to a little above 3 K. By the way, have you noticed how much faster the temperature falls at night in deserts and arctic areas where there is little water in the atmosphere?
Wayne Delbeke May 17, 2017 at 5:57 pm The 1″ of additional sea level is the amount of water that is stored and impounded behind the dam. If all dams released the entire water volume then all those tens of millions of acre feet storage would increase the ocean level by the amount of water behind the dam which is calculated to be .75″ to 1.25″. Most dams are operated at FSL (Full Supply Level) for maximum efficiency such as electricity generation. That is considered ‘dead storage’ for the water that is stored behind the dam under the FSL. After the dam is full of water, then what you say about the river eventually flowing to the ocean is correct. It is delayed storage that is stored behind the dam that we are talking about regarding what the ocean level would have been had no dams ever been built. Pretty straight forward logic, so wonder how you arrive at a different conclusion?
I have a feeling (like many studies) this is a way to phrase the study in a way which makes it sound more significant than it is.
I suspect that the amount of organic carbon moving from land to ocean is significantly less than the amount of carbon dioxide emitted from energy sources. It’s probably orders of magnitude less.
It other words, it makes the scientists feel good about the importance of their study (and I’m sure there are impacts in the river), but it does not make the results significant.
Do old lakes formed by natural dams trap carbon or nutrients differently than man-made dams? How is one different from the other?
The water level usually changes faster and more erratically in dams. This probably makes them less efficient sediment traps. Occasionally dams are built specifically for trapping sediments (e. g. from old mines or contaminated landfill sites upstream). In such cases one always tries to keep the water-level as constant as possible to encourage plant growth in the dam and enhance sediment capture.
I know you’ll find this hard to believe but, recently I’ve been studying the role of fluff in my navel. Quelle horreur that even without a superduper mega
willy enhancercomputer that because I am the Key researcher, I have found out what a Key role this Key fluff plays in my Key navel.It is simply gobsmackingly Key what a Key role it plays.
At least its a bit of fun and I try to positive about it, unlike these Key researchers. Why so relentlessly negative.
These lakes behind dams are massive sediment traps and as such should be regarded as a fantastic resource.That stuff, muddy, dirty, smelly and generally yuk is the concentrated goodness from large areas of land, farmland, forest whatever. It is all the trace elements and micronutrients plants need to grow – despite the assertions from many parties that CO2 is the only thing plants seem to need.
That smelly dirty yuk should be dredged out of the lakes, taken back up the hill it washed down and put/spread/dispersed across the land it originally came from
Dams are a brilliant things for doing that because otherwise all this goodness goes out into the sea and is lost, pretty well, forever.
Why don’t these supposedly educated people know this?
My wife is my key researcher. Every day I’m asking her, “Honey, do you know where I left my keys?”
Many dams have been designed with low level conduits to not only release sediments at freshet/high water flows, but also to release lower temperature water into the river to try and simulate what natural water temps would be if not for the dam.
Great idea on using the sediment from the bottom of the reservoirs. Probably the best pre-fertilized soils on earth. The Nile is one good example of the river silt being blocked. Having said all this about dams, I still think dams are very net positive to humans, although perhaps we can be smarter on how we use them and the precious fresh water they store.
WTF is “organic carbon”? Organic chemistry is a chemistry subdiscipline involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.
And when did silicon become a “nutrient”? Silicon is much more abundant than any other element, apart from the oxygen. It constitutes over 25% of the solid Earth’s crust.
Apparently no rational editor looked at this.
I guess diamonds and possibly graphite might be classed as “inorganic carbon”. The carbon in (natural) diamonds has probably never been part of organic compounds, graphite is more doubtful, it might well be highly modified organic materiel in some cases.
And, yes, dissolved silicon is a nutrient. Ask any diatom or radiolarian (or even grass for that matter). They all take up dissolved silica from water and use it as a structural material, just av we do with calcium.
“Inorganic carbon” is probably carbonate or bicarbonate. These are in solution, so they won’t get trapped behind dams. “Organic carbon” is presumably plant debris. which will get trapped. So there is some sense and logic there; don’t be too quick to dismiss everything just because it’s “green”.
Previous enviro-gripes about dams have focused on methane from trees and stuff buried by reservoirs. Also organo-mercury compounds allegedly leached from flooded soils and vegetation. These people have invented a whole new class of environmental destruction – “interrupting the carbon cycle”. Oh the humanity!
Organic chemistry is the study of carbon containing compounds. However, some carbon containing compounds are considered inorganic.
From wikipedia: “For historical reasons discussed below, a few types of carbon-containing compounds, such as carbides, carbonates, simple oxides of carbon (for example, CO and CO2), and cyanides are considered inorganic.[3] The distinction between organic and inorganic carbon compounds, while “useful in organizing the vast subject of chemistry… is somewhat arbitrary””
Whilst arbitrary, the distinction between organic and inorganic carbon is common and useful.
DAM!
Dams – the new fudge factor for GCMs. The more they tweak them, the more they fail.
Glacial Lake Missoula had verifiable and enduring environmental impacts on both Montana and Washington states, but that was a result of global warming 15,000 years ago!
http://www.glaciallakemissoula.org/story.html
Glacial Lake Missoula at 2,100 km3 was small fry. Glacial Lake Agassiz was 15,000-40,000 km3 and the West Siberian ice-dammed lake during the penultimate glaciation was 75,000 km3.
Now that is what i call a dam. And all three drained catastrophically due to global warming. Must have been all those damn neanderthalers with SUVs.
Barney and Fred ? Yabba dabba do!
Does this mean things are better or worse than they thought re the impact to Carbon Dioxide. Are the models even much worse than we already know?
“The study, conducted by researchers at the University of Waterloo and the Université libre de Bruxelles, appears in Nature Communications. It found that man-made dam reservoirs trap nearly one-fifth of the organic carbon moving from land to ocean via the world’s rivers.
While they can act as a significant source or sink for carbon dioxide, reservoirs are poorly represented in current climate change models.”
Very likely they don’t have the faintest idea whether they are net sources or sinks.
On balance I think more likely sinks. Lakes (and dams) trap organic sediment which, if it continued to the sea would probably get eaten and metabolized into CO2. On the other hand they also trap some nutrients that would otherwise be used by marine autotrophs, thereby absorbing CO2, but then most of those autotrophs would get eaten and metabolized back into CO2….
If I could use the bullshit from one of these “studies” in my garden I could feed my entire neighborhood.
Torpedo the dams! Full speed reverse!!
A measureable effect from reducing the DOC, silica, and phosphorus nutrients delivered to the ocean via rivers? I doubt it, especially since there is fertilizer runoff these days and iron is the limiting factor for most ocean primary production. However, there is certainly a measureable effect from reduced sediment load in general, and nowhere is it more noticeable than the Mississippi Delta.
Perhaps some of the energy produced by hydroelectric should go into dredging the trapped sediments and sending them downstream.
“and nowhere is it more noticeable than the Mississippi Delta.”
The Nile Delta is in at least as much trouble as the Mississippi Delta.
Limiting phytoplankton nutrients off the Mississippi Delta have been reported as nitrogen, phosphorus, and silica. There is lots of organic matter and production there. The Aswan dam collapsed the Israel sardine fishery, because the Mediterranean current off the Nile delta goes north.
Is increased carbon dioxide indirectly slowing erosion, therefore sediment and nutrient export, some collected by dams? HMMM?
I read here in the past that the water behind dams in Siberia catches the cold snow-melt water in the spring and gradually releases it over the summer and fall, during which time it’s warmed in the sun. This warmer water might be a major cause of the decline in arctic sea ice.
Oddly the opposite seems to be the case:
http://onlinelibrary.wiley.com/doi/10.1029/2006JG000370/full
Is this supposedly news? The consequences of changes down stream are an open question. How do the changes measure up against what happened when steam flows were unobstructed?
A previous study sought to raise alarms about dams by claiming methane emissions will rise from the reservoirs. Serious researchers found otherwise.
Over the last 30 years, CH4 in the atmosphere increased from 1.6 ppm to 1.8 ppm, compared to CO2, presently at 400 ppm. So all the dam building over 3 decades, along with all other land use was part of a miniscule increase of a microscopic gas, 200 times smaller than the trace gas, CO2.
Studies are here: https://rclutz.wordpress.com/2017/02/27/reservoirs-and-methane-facts-and-fears/
The bottom line of the paper is a no-brainer:
Of course dams change flow. How could they not? I see nothing in the above (press release?) that tells me that this is thus important, that it meets any standard of Minimal Climatically Important Difference.
It might — but nothing above shows that it is or even more than “might be”.
Taylor Maavara has proven that the attribute required to be a PhD student at Waterloo is a total absence of brain cells.
1) What is the effect of removing all of those acres of carbon sink which results when the reservoirs behind the newly constructed damns are filled?
2) How much additional carbon sink would be created by the removal of the damns ?
3) Is the difference too small to bother including its effects in the calculations of the models?
4) Has anyone actually performed the necessary calculations to make such determinations?
Forget the Carbon…these things are pumping vast quantities of ‘Water Vapour’ into the atmosphere! We all know that WV is a potent ‘greenhouse gas’!
Throw in the extra WV being pumped into our atmosphere from irrigation and you’re looking at a nightmare, tipping point catastrophic situation.
I am aware of the difference between CO2 and H2O but I was just wondering if anyone had any idea of the difference. The alarmist seem to emphasize CO2 so much especially when their remarks are intended for the public in general and for the MSM.
I decided several months ago that the only way that I would be able to get at the facts was to take it upon myself to look up and read the various papers and articles and that I could not rely upon anyone else. This site has been a God send in that regard and I am always interested in the comments section for each item posted.
One of the most obvious differences between CO2 and H2O is that CO2= 1/25th part of ONE percent of the atmosphere whereas H2O = >4%<….and is in LIMITLESS supply. I think that's what scientists call 'an order of magnitude'!!
crowcane. In this context the big difference is that water drops out of the atmosphere rapidly whereas CO2 does not. If you emit lots of water vapor it does not change the level of water in the atmosphere except locally over a short period.
Imagine a chimney emitting water vapor and CO2. The water vapor would increase humidity. When RH reaches 100% the water vapor condenses and falls to Earth. Quite soon all this added water will be removed from the atmosphere due to increased RH.
In contrast, the CO2 will never condense and fall to Earth but is removed by much slower processes. In a week or so all that water has been removed, but essentially all the CO2 is still there. This is why we are not concerned over water emissions. Emissions make essentially no difference to the level of water in the atmosphere.
We have measured the levels of CO2 in the atmosphere and they have risen by 40% or so – the Keeling curve. The amount of water in the atmosphere has not (substantially) changed over this period.
Whether you think the increase in CO2 is from fossil fuels or some other process, it is undeniable that CO2 is behaving totally differently from water in the atmosphere.
Seaice 1. Humans are causing additional water vapor 24/7 into the atmosphere that is a much stronger GHG overall than CO2 ever will be. Plus the additional water vapor that does turn to rain is over and above what natural rainfall would have been if not for the anthropogenic water vapor and can be considered responsible for more intense flooding events. Trying to say that human caused water vapor is a non issue is said only so that CO2 can be further demonized according to your religion.
Seaice,
It doesn’t matter that water vapor rains out more quickly than CO2 leaves the air. The fact is that there is on the order of 100 times more H2O in the air than CO2. If you believe the pack of lies perpetrated by IPCC and its consensus imps, then more CO2 also means more H2O, which is the only way they can gin up worrisome warming.
CO2 isn’t a pimple on the posterior of H2O. Most of their absorption bands overlap anyway, so any possible effect from CO2 is already swamped by the far more important GHG.
Ron. Humans are adding water, which just as quickly falls out of the atmosphere. It is a condensing vapor. Otherwise we would have something like the Keeling curve for water, showing a steadily increasing level of water in the atmosphere. We clearly do not see this. This is because the extra water falls out of the atmosphere when it condenses. The extra rainfall due to human emissions of water is miniscule compared to the amount of water that evaporates naturally.
Water in the atmosphere is about 15,000GT. Water flux (evaporation and precipitation, which are the same aount) is 505,000GT per year. The flux is much greater than the reservoir. Small additions from humans make no difference to the reservoir
CO2 in the atmosphere is about 710GT. CO2 flux is about 220GT per year. The flux is much smaller than the reservoir. The small additions of CO2 to the atmosphere remain in the atmosphere, resulting in a steadily increasing level. This has been measured and is pretty much solid – unless you wish to question these measurements?
You argue that human emitted water is responsible for more intense flooding events. This sounds like nonsense to me, but perhps you can back this up with some evidence?
Chimp.
“It doesn’t matter that water vapor rains out more quickly than CO2 leaves the air. The fact is that there is on the order of 100 times more H2O in the air than CO2. ”
Nothing I said disputes the relative levels of CO2 and water in the atmosphere. My point is that water we add through emissions does not increase the amount of water in the atmosphere becase it condenses out, whereas the CO2 we emit does increase the level in the atmosphere. Do you disagree with this?
If you do disagree with this,, can you explain why we do not have something like the Keeling curve for water, showing steadily increasing levels of water in the atmosphere that humans have emitted?
No, of course you can’t, because all that extra water has simply condensed out.
I don’t think the trapped carbon, etc. is the major impact of the dams. Free flowing rivers deposit a lot of dirt, sand, silt, rocks, etc., which act as a counter to beach erosion caused by tides, storms, etc. There can also be a reduction of organic materials that are food to fish and shell fish in the area. I think that dams serve a very useful purpose, but if you’re going to look at a potential negative impact, I don’t think it is carbon.
So urbanization allegedly has a teenie-tiny influence on global temps…but dams certainly do?
What they appear to be insinuating is that of the organic carbon (i.e. not CO2 but higher molecules up to and including twigs and leaves) has a different chemical fate if some of it gets stuck for a while behind a damn. I just don’t buy that it will be significantly different in the long term or that the amount is significant on a global scale, even if they were talking about 100% of it and not 20%.
When those pseudo scientists turn on a tap they expect, demand even that water will flow out of that tap in a never ending stream.
I bet they never ever think of where that water they so depend on for so many things that make their lives so easy compared to those who have no such taps, comes from.
When those pseudo scientists reach for a food and vegie item off the shelves in the super markets I bet they never ever think of where the immense volumes of water that is needed and enables those vegies and food items to grow so prolifically and to be supplied in such quantities and at such low prices, ever comes from.
When they flush their waste down the toilet, I doubt that any of them ever think of or consider their own beliefs and understandings of where the immense volumes of water come from that enables such a huge waste disposal system to operate so efficiently and so unnoticed by the millions of those city’s inhabitants.
A human waste disposal system that is the ultimate key to being able to live in mankind’s cities, cities that are clean and healthy and relatively free from major diseases, cities that now house hundreds of millions of mankind’s numbers,all due to the availability of water in immense volumes from the dams that mankind has built on the rivers of Earth.
Gross hypocrisy and arrogance and ignorance and condescension does not sit well with those elitists who would preach to us on how we proles are ruining the planet by our desire to have a few life sustaining essentials such as water and food made cheaper and more easily available to the human race by building dams and power stations and sewerage systems that use lots of water from dams on river, dams and their waters that make life in mankind’s immense cities habitable and healthy for the billions who now live in those cities.
This one comes under Scott Adam’s “The Psychic Psychiatrist Illusion”, where the loser of the argument imaginings they can discern the inner thoughts and motives of strangers.